Level 3 - vial, cap, and septa kits. EPA Certified Screw Vial & Cap Kits. HPLC & GC Certified Screw Vial & Cap Kits for 2 mL Samples. Precleaned, EPA certified assembled kits; includes 40 mL screw vials and 24 mm. open top screw caps. 0.3 and 1.5 mL screw top vial-cap kits for analysis of small sample volumes.